We had thought about meeting in Hollywood, Nashville or New York. Then the phone rang late at night: could I be at a church an hour outside Chicago at 4.30pm the following day?

It was sunny in Joliet, a small town romantically pronounced 'Juliet', and inside the church, a couple were getting married. At the appointed time, I stood at the back, looking for clues amid the congregation. I peered at the bride (though I knew the person I was meeting was already married). I wondered if there was any significance in the church (it was Catholic; she is Protestant). Idle thoughts, but after a week of watching the high-earning action thrillers with which Ashley Judd has made her name, you begin to believe she may conduct her life along similar lines.

Just then, I saw a figure wearing a baseball cap and wildly oversized sunglasses, a get-up that shouted 'incognito' so loudly I recognised her at once. Judd shook my hand, introduced me to her two cockapoo dogs, Shug and Buttermilk, and said, as she settled onto a patch of lawn: 'Have you come all this way just for this?'

Although this was a touch worthy of Norma Desmond (how could I have had time to plan anything else?), I liked her very much. Underneath her glasses and her cap, she is intriguingly beautiful - not in the dazzling, smoothed-over way she appears on countless magazine covers, nor in the sleek and determined manner of her gutsiest heroines. In the flesh, there is something gentler about her, a little warmth and, perhaps, a little worry, as well as her much-feted poise.

After some small talk (Judd was there to accompany her racing driver husband; the circuit was nearby and she just spotted this church yesterday as she drove past), she came right out with it: 'Um,' she said, 'I'm getting a little uptight. Because this is a British newspaper.'

And? I asked.

'And I don't trust them at all. I was really nervous about this, because we just don't trust anybody from the UK.'

Despite the many interesting aspects of her role as Linda Porter in the film she is promoting, De-Lovely, Judd can't be unaware that it received rather thudding American reviews. As Cole Porter's wife, she plays a woman graciously devoted to a genius, despite his many homosexual affairs, but the potential complexity of this is blunted by the film's artless format. Her previous movie, Twisted - in which she plays a homicide cop - was released in the UK a few months ago, and coolly received.

But that's not what was bugging her. The problem, she said, was that her supposedly honky-tonk past had become 'so mythologised and ridiculous'. It has been said that Judd grew up 'without running water, without electricity', when the fact is that some of her relatives simply lived 'in an old-timey way by choice'. She is rumoured to have been so poor as a child she had to make her own soap, when she only made soap because her mother was interested in the craft of it.

Judd became exasperated as she spoke: 'It's like we're some portrait out of the Depression! It's about titillation, scandal or ruin; at the very least, it has to be about conflict. It's so reductive. It's not even that wonderful thing that Steinbeck said about "the end is always latent in the beginning". I don't recognise any of it! There's so much going on with my family story, which I probably will choose never to tell.'

She was born days after Martin Luther King was assassinated in the state where she now lives. She is the second daughter of Naomi Judd, a single mother who waitressed her way through college in order to become a nurse and then, when Ashley was 15, formed a singing duo with her other daughter, Wynonna. The Judds became one of the most successful acts in country music and spent their days on the road. Sometimes, Ashley went with them (reportedly making pocket money by cleaning their tour bus) and sometimes shunted between relatives.

'I coped very well in certain ways and in other ways I was very uncertain,' she told me. 'I think that school was like a potential disaster and I didn't really come into my own until college. I started to write; I had a lot of really strong feminist teachers.'

After studying French at the University of Kentucky, Judd drove a couple of thousand miles to try to make her way in Hollywood. David Letterman once joked: 'The Judds have another girl, but she's so ugly they keep her locked in a basement!', a quip she was soon to lay to rest. Her first film, a thoughtful, low-key independent called Ruby in Paradise, immediately put her on the map as an actress of sincerity and intelligence. But it wasn't until Jodie Foster pulled out of the thriller Double Jeopardy five years ago that she got the part that made the bucks.

Since then, Judd has played a series of strong women or, rather, in her own description, 'characters who are hurt in some way, and coping '. She has commanded salaries of more than $8 million, while to some extent turning her back on the Hollywood game. She lives with her husband, Dario Franchitti, and their multitude of pets in a house in Tennessee bought for her by her sister, who lives nearby. At 36, Judd has 'managed to do a lot of correcting' of a childhood she describes as 'totally chaotic'. Her sister once famously described it as 'putting the "fun" into "dysfunctional".'

Part of the problem with the family legend is that one of its chief mythologists is Judd's mother. In 1993, Naomi Judd published an autobiography called Love Can Build a Bridge. It was turned into a TV mini-series; Judd was asked to play her mother and ended up playing herself, a choice which has not prevented her from cursing as soon as the project is mentioned. (Wynonna said at the time that she would write a sequel entitled 'The Truth'.)

Now Naomi Judd has written a new self-help book (Naomi's Breakthrough Guide), in which she is given to motherly boasts - Ashley once beat a Nobel laureate at Trivial Pursuit - and more regrettable assertions, such as: 'Ashley is as slick as snot on a doorknob.'

How is Judd coping with the uninvited attention? 'Well, my friends have helped me with that. A lot of it is not totally true, but I just gloss over that. She's my mom and it's just as much her experience as it is mine.'

Last month, the three Judds went on Oprah. There ostensibly to discuss Wynonna's battle with her weight, the women mentioned a tricky family issue: Wynonna's father was not Ashley's, and Wynonna had not known this until she was 30 (10 years ago), but Ashley had known it all along. Why?

'What's more interesting to me,' Judd told me, 'is why I didn't just tell her right away, why I felt complicit in their secrecy. At the age of 17, I didn't realise that I had an independent mind, and could choose. That occurred to me recently. I thought, why the fuck didn't I tell her? I mean, ultimately, I did. I'm the one who told her.'

'In my next action movie,' Judd wrote in a diary recently, 'I am going to be an avenging angel of the sisterhood. I am going to work subtly and quietly in the dark, rescuing women from brothels in ways so covert that my movements will go unnoticed as a tiny radio continues to play in the background. Then, for the sequel, I will do a full-on superhero turn, upending poverty, banishing ignorance. I went to Pattaya tonight, an infamous red-light district here in Thailand. Can you tell?'

This summer, Judd, who is global ambassador for YouthAids, went on a trip to Cambodia and Thailand and became committed to rescuing some sex workers from their 'bondage'. She is a woman's woman, as might be understood from her background. She speaks of her three best girlfriends with bracing affection, unabashedly calls herself a feminist, is continually campaigning to help women register to vote and generally doing, as she puts it, 'anything Gloria Steinem asks me to'.

No matter how grand she may be in some respects - she is, for example, unapologetic about her reliance on her housekeeping 'staff' - Judd has a sensibility for solidarity. For her, to use a favourite word of hers, there is no 'disconnect' between the two.

As a teenager, Judd was 'always raising hell about something' and her activism work has allowed her to put to use 'a power I've always known I've had'. She has no more film projects until next year, but is very much looking forward to her next YouthAids trip, to Africa. In the meantime, she will be at home, reading, baking, teaching the odd geography lesson at her niece and nephew's school. She and Dario might try and learn Italian and...

Just then, the bride and groom walked up to where we were sitting. 'I apologise,' said the groom. 'I did not recognise you when we walked by.'

'That's OK,' Judd replied, with charm. 'You don't need to recognise me - you guys are the stand-out. This is your day.'

The bride giggled and said: 'Could you autograph our programme?'

Judd looked a little nervous. Someone was taking her picture. She forgot the groom's name as she inscribed their order of service. They chatted. They left. Judd looked resigned. 'Welcome to my life,' she said.